Cellulose-ether composition



Patentedisept. 8, 1925.

UNITED STATES PATENT OFFICE.

JOHZN DONOHUE, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

.CELLULOSE-ETHER COMPOSITION.

No Drawing.

To all whom it may concern:

Be it known that I, JOHN M. DONOHUE, a citizen of the United States of America, residin at Rochester, in the county of Mon- 6 roe an State of New York, have invented certain new and useful Improvements in Cellulose-Ether Compositions, of which the following is a full, clear, and exact specification.

7 10 This invention relates to solvents for 1nakappgar. I U. S. Patent No. 1,188,376 Lilienfeld, June 20, 1916, there are disclosed a series of alkyl ethersof cellulose. Certain of these are practically insoluble in water', and my invention relates, but is not limited, to the others having that property. While cellulose ethers form thin solutions in carbonates of the lower monohydroxy aliphatic alco hols, it has been found that such single solvents by themselves do not dissolve a sutficient proportion of the ethers to make a desirable thick flowable composition or'dope, such as may be used in the manufacture of photographic film base by customary methods or in the other plastic arts.

I have discovered that an adequately strong and useful solvent may be prepared by mixing one or more of the carbonic acid esters of the lower monohydroxy aliphatic alcohols with one or more of the lower monohydroxy aliphatic alcohols themselves.

In other words, I have discovered that mixtures of these ingredients have a greater solvent action on cellulose ethers than similar weights of such solvents when employed by themselves. By lower monohydroxy aliphatio alcohols I mean those having less than 6 carbon atoms.

Application filed February 24, 1923. Serial No. 621,085.

WVhile the ingredients may be mixed in widely varying proportions, it is noted, by

way of example, that a particularly useful composition can be prepared by mixing equal parts by weight of ethyl carbonate and methyl alcohol. In the preferred form of my invention I dissolve 1 part by Weight of cellulose ether, say water-insoluble ethyl cellulose, in from 5 to 7 parts by weight of the solvent mixture. The ingredients by themselves are not sufliciently powerful to make properly flowable solutions of this strength. I Of course, the proportion of mixed solvent or the proportion of the volatile ingredients may be increasedto adapt the composition to the lacquerin art, as will be understood by persons skified therein. The rate of evaporation may be controlled by substituting higher alcohols than the methyl. Likewise greater volatility is obtained when methyl carbonate is substituted for ethyl carbonate and less volatility is ob tained when the various propyl, butyl and amyl carbonates are used.

Other substances which impart additional suppleness, or incombustibility, or other qualities, to the film may also be added to the dope, such, for instance, as triphenyl or tricresyl phosphate, monochlornaphthalene, camphor, etc. The ingredients are of the ordinary commercial type and sufficiently purified for the process of film manufacture,

so as to give a dope yielding films having the proper relative freedom from color. The viscous-flowable dope above described can be used in connection with the usual filmforming apparatus without the necessity of a lower monohydroxy aliphatic alcohol, said ingredients being homogeneously mixed in unprecipitated form.

a 2. A composition of matter comprising cellulose ether dissolved in a mixture of a lower monohydroxy aliphatic alcohol and a carbonic acid ester of a lower monohydroxy aliphatic alcohol,

3. A composition of matter comprisin cellulose ether dissolved in a mixture 6i ethyl carbonate and methyl alcohol.

4. A fiowable film-forming composition comprising 1 part of cellulose ether dissolved in from 5 to 7 parts by weight of a mixture of a lower monohydroxy aliphatic alcohol and a carbonic acid estefof a lower monohydroxy aliphatic alcohol.

5; A composition of matter comprising cellulose ether dissolved in a mixture of substantially equal parts'by weight of a lower 2 JOHN M. DONOHUE. 

